FillObjectVector and FillContainerVector iterate through the vector and in each position create a new object. Each object is independent from the rest.What I want to know if it it possible to launch all of the parallel_for's at the same time. Would it be a good idea?.

Depending on the number of memory channels available, if you have two then consider parallel_invoke with each vector listed in the task list using standard for(... to fill/copy the data. On such a system using more than two threads to perform the copy may be counter productive.